Confirm the exact configuration
Use the manufacturer part number and model code—not appearance alone. Connection, size, material, voltage, pressure, seal, and control options can differ within the same product family.

Thorlabs
The Thorlabs 390021-E is an unmounted Geltech aspheric lens featuring an 11.0 mm focal length, a 0.18 numerical aperture, and an anti-reflective coating optimized for the 3 to 5 µm spectral range. Released on February 21, 2012, this component reached its end-of-life status when Thorlabs officially discontinued it on December 9, 2014. Submit the exact part number, quantity, and application requirements to request a quote for remaining inventory.
For a faster response, include quantity, condition, and delivery destination.
Verified configuration
Engineering context
Use the manufacturer part number and model code—not appearance alone. Connection, size, material, voltage, pressure, seal, and control options can differ within the same product family.
Provide quantity, delivery country and ZIP/postal code, required condition, target date, and photographs of the existing nameplate when available.
Our sourcing response is prepared against Thorlabs 390021-E. Final compatibility remains subject to the machine manufacturer’s requirements and complete application data.